Two inmates who barricaded themselves up a tower at Auckland's maximum security prison have abandoned their protest.

The Paremoremo inmates spent the weekend in the disused tower with minimal food and blankets in inclement weather.

One of them is believed to have been serial escaper Aaron "Houdini" Forden.

One of the men surrendered yesterday at 1.30pm, having been up the tower for more than 50 hours. His companion, believed to be Forden, gave up about 7.30pm.

The men each face an internal charge of breaching prisoner protocol and would spend 14 days in an isolated cell for 23 hours at a time, Prison Services general manager Jeanette Burns said.

The pair scrawled toothpaste on a window to indicate their peaceful protest was in defiance of their placement at the Auckland East facility.

They also wished to speak with high-profile lawyer and Prison Reform Society president Peter Williams, QC.

Williams has spoken out against the treatment of high security prisoners at Paremoremo.

Some prisoners are kept in cages, and D-block inmates were often locked up with nothing to do but lie on their bunks, he said.

Williams said he recently visited a Paremoremo prisoner who was segregated from inmates for six months.

Prisoners in isolation have trouble accessing rehabilitation courses such as for drugs, alcohol and anger, he said.

Red-haired Forden was on the run from police three times last year, and is known for changing his appearance.

He became the first person to escape from the new $218 million Mt Eden Corrections Facility in October last year, where two staff members have since been stood down.

He infamously crawled through roof cavities at Mt Eden prison and used knotted-together sheets to lower himself over barbed wire in 2008.

A full investigation will be launched after the prisoners accessed the tower from an unmanned exercise yard around 10am on Friday.

The yard is monitored with cameras.

The prison was on lock-down over the weekend, with visitors barred.

Inmates were prevented from making phone calls, exercising and taking showers until extra staff became available on Sunday.

Burns said staff were always confident the prisoners would retreat on their own accord.

For safety reasons prison guards were not allowed to confront the men up the tower, as they have not been trained to scale heights, Burns said. The prisoners were always allowed to surrender peacefully and negotiators worked with them through the weekend, she said.

The public was never in danger, as the inmates would have had to get through razor wire and jump a great distance to escape, she said.